The role of short-chain fatty acids in the interplay between diet, gut microbiota, and host energy metabolism

Targeting the Gut Microbiota's Role in Host Energy Absorption With Precision Nutrition Interventions for the Prevention and Treatment of Obesity

The field of precision nutrition aims to develop dietary approaches based on individual biological factors such as genomics or the gut microbiota. The gut microbiota, which is the highly individualized and complex community of microbes residing in the colon, is a key contributor to human physiology. Although gut microbes play multiple roles in the metabolism of nutrients, their role in modulating the absorption of dietary energy from foods that escape digestion in the small intestine has the potential to variably affect energy balance and, thus, body weight. The fate of this energy, and its subsequent impact on body weight, is well described in rodents and is emerging in humans. This narrative review is focused on recent clinical evidence of the role of the gut microbiota in human energy balance, specifically its impact on energy available to the human host. Despite recent progress, remaining gaps in knowledge present opportunities for developing and implementing strategies to understand causal microbial mechanisms related to energy balance. We propose that implementing rigorous microbiota-focused measurements in the context of innovative clinical trial designs will elucidate integrated diet-host-gut microbiota mechanisms. These mechanisms are primed to be targets for precision nutrition interventions to optimize energy balance to achieve desired weight outcomes. Given the magnitude and impact of the obesity epidemic, implementing these interventions within comprehensive weight management paradigms has the potential to be of public health significance.

A Cascade of Microbiota-Leaky Gut-Inflammation- Is it a Key Player in Metabolic Disorders?

PURPOSE OF REVIEW

This review addresses critical gaps in knowledge and provides a literature overview of the molecular pathways connecting gut microbiota dysbiosis to increased intestinal permeability (commonly referred to as "leaky gut") and its contribution to metabolic disorders. Restoring a healthy gut microbiota holds significant potential for enhancing intestinal barrier function and metabolic health. These interventions offer promising therapeutic avenues for addressing leaky gut and its associated pathologies in metabolic syndrome.

RECENT FINDINGS

In metabolic disorders such as obesity and type 2 diabetes (T2D), beneficial microbes such as those producing short-chain fatty acids (SCFAs) and other key metabolites like taurine, spermidine, glutamine, and indole derivatives are reduced. Concurrently, microbes that degrade toxic metabolites such as ethanolamine also decline, while proinflammatory, lipopolysaccharide (LPS)-enriched microbes increase. These microbial shifts place a higher burden on intestinal epithelial cells, which are in closest proximity to the gut lumen, inducing detrimental changes that compromise the structural and functional integrity of the intestinal barrier. Such changes include exacerbation of tight junction protein (TJP)s dysfunction, particularly through mechanisms such as destabilization of zona occludens (Zo)-1 mRNA or post-translational modifications. Emerging therapeutic strategies including ketogenic and Mediterranean diets, as well as probiotics, prebiotics, synbiotics, and postbiotics have demonstrated efficacy in restoring beneficial microbial populations, enhancing TJP expression and function, supporting gut barrier integrity, reducing leaky gut and inflammation, and ultimately improving metabolic disorders. This review summarizes the mechanisms by which gut microbiota contribute to the development of leaky gut and inflammation associated with metabolic syndrome. It also explores strategies for restoring gut microbiota balance and functionality by promoting beneficial microbes, increasing the production of beneficial metabolites, clearing toxic metabolites, and reducing the proportion of proinflammatory microbes. These approaches can alleviate the burden on intestinal epithelial cells, reduce leaky gut and inflammation, and improve metabolic health.

Impact of Probiotic Formula (Lacto-5X) on Constipation: Improvements in Gastrointestinal Symptoms, Gut Microbiome, and Metabolites

Constipation is characterized by low frequent stools and difficult stool passage. Approximately 16% of the global population experiences these symptoms. Probiotics have shown promise in improving constipation symptoms by modulating the gut microbiome. This study aims to evaluate the effects of a probiotic formula (Lacto-5X) on bowel habits, gastrointestinal symptoms, gut microbiome, and metabolites in adults with mild constipation using a randomized, double-blind, placebo-controlled clinical trial design. At the 4-week endpoint, the Probiotic group had significant improvements in stool consistency, stool frequency, abdominal pain, and straining compared to the Placebo group. Satisfaction with bowel habits and improvement in overall intestinal health were significantly higher in the Probiotic group. Microbiome analysis revealed a significant increase in the abundance of Lactobacillus and L. plantarum in the Probiotic group at the 4-week endpoint. Metabolome analysis showed that L-proline level in the Probiotic group decreased, while threonic acid level increased at the 4-week endpoint compared to the Placebo group. However, these improvements were not sustained at the 8-week follow-up point. Lacto-5X changes the gut microbiome, leading to changes in metabolites, and it induced improved constipation symptoms. Continuous intake may be necessary to maintain these effects. Further studies are needed to explore the long-term efficacy of Lacto-5X.

Dietary fatty acids promote gut health in weaned piglets by regulating gut microbiota and immune function

Background

Post-weaning diarrhea in piglets is a common challenge that adversely impacts growth performance and increases mortality, leading to severe economic losses. Medium-chain fatty acids (MCFA) and short-chain fatty acids (SCFA) are frequently used as feed additives due to their bioactive properties. This study evaluated the effects of two different blends of MCFA and SCFA (VSM and VS + VM) as alternatives to zinc oxide (ZnO) on growth performance, nutrient digestibility, oxidative stress, inflammatory, and gut microbiota composition in weaned piglets.

Methods and results

A total of 108 piglets (8.22 ± 0.51 kg) were randomly assigned to three treatments: control (CON, basal diet + ZnO), VSM (basal diet + higher MCFA and lower SCFA content) and VS + VM (basal diet + higher SCFA and lower MCFA content). Results indicated that Both VSM and VS + VM, can replace ZnO to relieve diarrhea of weaned piglets as evidenced by increased average daily gain (ADG) and decreased feed to gain ratio (F/G) in 1-15 days, with no difference in final body weight compared to the CON group. Additionally, dietary MCFA and SCFA supplementation improves anti-oxidative and anti-inflammatory capacity by decreased of malondialdehyde (MDA) activity, and inhibited proinflammatory cytokine tumor necrosis factor α (TNF-α) and interleukin (IL-1β, IL-17A) secretion. Further study showed that the protective effect of MCFA and SCFA were associated with restoring gut barrier, upregulating abundances of Lactobacillus and Roseburia of piglets.

Interpretation

Collectively, the combination of MCFA and SCFA alleviated oxidative stress, modulated inflammation, and supported gut barrier function in weaned piglets, offering a promising alternative to ZnO, with VSM showing superior effects.

Green jackfruit flour ameliorates MASH and development of HCC via the AMPK and MAPK signaling pathways in experimental model systems

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a serious public health concern. Given the paucity of approved therapeutic strategies for this lifestyle disorder, dietary interventions may prove effective. We evaluated the mechanisms of how green jackfruit flour (JF) ameliorates metabolic-dysfunction-associated steatohepatitis (MASH) and halts the progression to hepatocellular carcinoma (HCC). The study used murine models of MASH and MASH-HCC that closely mimic human MASLD. C57Bl/6 male mice were fed with chow or western diet with normal or sugar water for 12 weeks, then randomized to receive either 5 kcal% green jackfruit flour (JF) or an equal volume of placebo flour (PB). JF significantly reduced body weight, liver injury, and insulin resistance, and alleviated obesity, steatosis, inflammation, fibrosis, and tumor development in WDSW or WDSW/CCl4 mice compared to placebo. Furthermore, JF activated AMPK (AMP-activated protein kinase) and inhibited MAPK (mitogen-activated protein kinase) signaling pathways in MASH and MASH-HCC models, respectively. Sodium propionate treatment, the primary short-chain fatty acid entering the liver from JF's soluble fiber microbial fermentation, further supported these mechanistic insights. Hence, our findings present strong evidence of JF's therapeutic potential in attenuating MASH and MASH-HCC, warranting further investigation of JF's efficacy as a dietary intervention in clinical trials.

Comparative Study on the Effects of Selenium-Enriched Yeasts with Different Selenomethionine Contents on Gut Microbiota and Metabolites

Selenium is an essential trace element for human health, but it mainly exists in an inorganic form that cannot be directly absorbed by the body. Brewer's yeast efficiently converts inorganic selenium into bioavailable organic selenium, making selenium-enriched yeast highly significant for human health research. Selenomethionine (SeM) is an important indicator for evaluating the quality of selenium-enriched yeast. Brewer's yeast was selected as the experimental subject, and the digestion of this yeast (Brewer's yeast) was simulated using an in vitro biomimetic gastrointestinal reactor to evaluate the effects of selenium-enriched yeast with various SeM levels on the gut flora of a healthy population. The experimental design comprised normal yeast (control group, OR), yeast containing moderate SeM levels (selenium-enriched group, SE), yeast containing high SeM levels (high-selenium group, MU), and a commercially available group comprising selenium-enriched yeast tablets (MA). The MU group exhibited a significantly higher concentration of short-chain fatty acids than the OR and MA groups during 48 h of fermentation, with significant differences observed (p < 0.05). Sequencing results revealed that the MU group showed significantly increased relative abundances of Bacteroidetes and Actinobacteria, while exhibiting a decreased ratio of Firmicutes to Bacteroidetes, which may simultaneously affect multiple metabolic pathways in vivo. These findings support the theory that selenium-enriched yeast with a high SeM has a more positive effect on human health compared with traditional yeast and offer new ideas for the development and application of selenium-enriched yeast.

Beyond soluble and insoluble: A comprehensive framework for classifying dietary fibre's health effects

Despite evolving definitions, dietary fibre classifications remain simplistic, often reduced to soluble and insoluble types. This binary system overlooks the complexity of fibre structures and their diverse health effects. Indeed, soluble fibre is not just soluble but has important qualities such as fermentability, attenuating insulin secretion, and lowering serum cholesterol. However, this limited classification fails to account for dietary fibre diversity and predict their full range of physiological effects. This article proposes a holistic classification framework that accounts for different fibre types and can be used to accurately infer their physiological outcomes. This proposed classification framework comprises of five constituents: backbone structure, water-holding-capacity, structural charge, fibre matrix and fermentation rate. This model more accurately captures the structural and functional diversity of dietary fibres, offering a refined approach to predicting their health benefits.

p-Hydroxycinnamic Acids: Advancements in Synthetic Biology, Emerging Regulatory Targets in Gut Microbiota Interactions, and Implications for Animal Health

p-hydroxycinnamic acids (p-HCAs), a class of natural phenolic acid compounds extracted from plant resources and widely distributed, feature a C6-C3 phenylpropanoid structure. Their antioxidant, anti-inflammatory, and antibacterial activities have shown great potential for applications in food and animal feed. The interactions between p-HCAs and the gut microbiota, as well as their subsequent effects on animal health, have increasingly attracted the attention of researchers. In the context of a greener and safer future, the progress and innovation in biosynthetic technology have occupied a central position in ensuring the safety of food and feed. This review emphasizes the complex mechanisms underlying the interactions between p-HCAs and the gut microbiota, providing a solid explanation for the remarkable bioactivities of p-HCAs and their subsequent impact on animal health. Furthermore, it explores the advancements in the synthetic biology of p-HCAs. This review could aid in a basis for better understanding the underlying interactions between p-HCAs and gut microbiota and animal health.

Dietary Short-Chain Fatty Acids Supplementation Improves Reproductive Performance and Gut Microbiota in Gilts

BACKGROUND

Short-chain fatty acids (SCFAs) have emerged as critical modulators of female reproductive function and host gut microbiota.

OBJECTIVES

This study aimed to investigate the impact of dietary SCFAs supplementation on reproductive performance and gut microbiota in gilts, and to elucidate the underlying mechanisms.

METHODS

Eighty gilts (95 d old) were randomly assigned to either a control group (Ctrl, 40 gilts) receiving a basal diet, or a SCFAs treatment group (SCFAs, 40 gilts) receiving a basal diet supplemented with 0.13% sodium acetate, 0.11% sodium propionate, and 0.09% sodium butyrate. At third estrus, 13 gilts (6 from Ctrl and 7 from SCFAs) were killed for follicular development and gut microbiota analysis, whereas the remaining gilts completed gestation for reproductive performance assessment.

RESULTS

SCFAs group had higher total number born (11.97 compared with 9.44) and total number born alive (11.28 compared with 9.34) compared with Ctrl group (P < 0.05). SCFAs group had increased counts of secondary follicles (36.14 compared with 26.83), antral follicles (10.29 compared with 6.67), and corpus luteum (25.09 compared with 19.33), alongside had reduced atretic follicles (15.32 compared with 20.67) compared with Ctrl group (P < 0.05). Proteomic analysis revealed that SCFAs-induced differentially expressed proteins (DEPs) were significantly enriched in the follicular development-related pathways (P < 0.05). Apoptosis-related DEPs positively correlated with follicular development indices (P < 0.05), consistent with the reduced apoptosis observed in ovarian granulosa cells of the SCFAs group. Additionally, SCFAs supplementation improved both the composition and alpha-diversity (P < 0.05) of gilts' gut microbiota. Furthermore, both the SCFAs-enriched bacteria and plasma SCFAs concentrations showed positive associations with gilts' follicular development indices (P < 0.05).

CONCLUSIONS

Dietary SCFAs supplementation enhances reproductive performance in gilts by promoting ovarian follicular maturation and optimizing gut microbiota composition.

Dietary Fibre Modulates Gut Microbiota in Late Pregnancy Without Altering SCFA Levels, and Propionate Treatement Has No Effect on Placental Explant Function

Background/Objectives: Dietary fibre promotes health, partly by mediating gut microbiota and short-chain fatty acid (SCFA) production. Pregnancy alters the relationship between dietary composition and the gut microbiota, and it is unclear if fibre intake during late pregnancy alters the abundance of SCFA bacteria and circulating SFCA concentrations. The aim of this study was to determine the impact of dietary fibre on faecal microbiome composition and circulating concentrations of SCFA acetate, butyrate, and propionate in late pregnancy. We also aimed to assess the impact of propionate treatment on placental function using cultured placental explants. Methods: 16S rRNA gene amplicon sequencing was performed on faecal DNA collected at 28 weeks of gestation from participants enrolled in the SPRING cohort study consuming a low or adequate fibre diet. Circualting SCFA were assessed. Placental explants were treated with sodium propionate. Results: Fibre intake did not impact microbial diversity or richness but did impact the abundance of specific bacterial genera. Pregnant participants with low-fibre diets had a greater abundance of Bacteroides and Sutterella, and dietary fibre intake (mg/day) negatively correlated with genera, including Sutterella, Bilophila, and Bacteroides. SCFA concentrations did not differ between groups but circulating concentrations of acetate, propionate, and butyrate did correlate with the abundance of key bacterial genera. Propionate treatment of placental explants did not alter mRNA expression of fatty acid receptors, antioxidants, or markers of apoptosis, nor did it impact pAMPK levels. Conclusions: This study demonstrates that the impact of dietary fibre on SCFA concentrations in pregnant women is modest, although this relationship may be difficult to discern given that other dietary factors differed between groups. Furthermore, this study demonstrates that propionate does not impact key pathways in placental tissue, suggesting that previous associations between this SCFA and placental dysfunction may be due to other maternal factors.

Changes in gut microbiome following anti-tuberculosis treatment: a prospective cohort from eastern China

BACKGROUND

The treatment of people with tuberculosis necessitates the administration of both broad-spectrum and narrow-spectrum antibiotics for a minimum duration of six months. Prolonged antibiotic therapy may result in dysregulation of the gut microbiota, potentially influencing the onset and progression of tuberculosis. There is a paucity of studies focus on the characteristics of gut microbiota changes at various time points during tuberculosis treatment. This study aims to elucidate the relationship between the composition of gut microbiota and their stage within anti-tuberculosis therapy.

METHODS

A multi-center, observational prospective cohort study was conducted at four designated hospitals in Jiangsu Province in eastern China. The Gastrointestinal Symptom Rating Scale was employed to evaluate the gastrointestinal discomfort experienced during anti-tuberculosis treatment. Fecal samples were collected at baseline before initiating anti-tuberculosis therapy and at the end of 2 months and 6 months during treatment. Total microbial genomic DNA was extracted and sequenced. Rarefaction curves and alpha diversity indices including observed operational taxonomic units, Chao1 richness and Shannon index were calculated.

RESULTS

From October 2020 to December 2022, a total of 204 people with tuberculosis were diagnosed. Among these, 85 people with tuberculosis provided baseline, 2-month, and 6-month fecal samples. The average age was 41.8 ± 15.193 years, with a gender ratio of 77 males to 8 females. Only 28.2% of the cohort reported being free of gastrointestinal symptoms during anti-tuberculosis treatment. Anti-tuberculosis treatment significantly reduced gut microbiota diversity, with a transient decrease in alpha diversity indices observed after two months. A higher alpha diversity in baseline (Shannon index with mean ± standard deviation (SD) 2.92 ± 0.93 vs. 2.50 ± 0.84, P = 0.0014, inverse Simpson's index with 11.9 ± 8.66 vs. 7.87 ± 6.42, P = 0.0012), compared with people with tuberculosis after 2 months of treatment. No significant differences were identified between 2 months of treatment and at the end of treatment microbiota diversity (Shannon index 2.50 ± 0.84 vs 2.58 ± 0.81, P = 0.55, inverse Simpson's index 7.87 ± 6.42 vs 11.90 ± 8.66, P = 0.43).

CONCLUSIONS

Findings from our study show that anti-tuberculosis treatment has profound effects on people with tuberculosis gastrointestinal function and the gut microbiota, particularly during the intensive phase of therapy. After the intensive treatment phase, the gut microbiota has partially recovered, but it is an extremely slow process.

Fecal Microbial Profiles and Short-Chain Fatty Acid/Bile Acid Metabolomics in Patients With Age-Related Macular Degeneration: A Pilot Study

Purpose

Age-related macular degeneration (AMD) is a multifactorial disease, and studies have implicated the role of gut microbiota in its pathogenesis. However, characterization of microbiome dysbiosis and associated microbial-derived metabolomic profiles across AMD stages remains unknown. In this pilot study, we explored how gut microbiome composition and gut-derived metabolites differ in AMD.

Methods

Our pilot study analyzed fasted stool samples that were collected from 22 patients at a tertiary academic center. Subjects were classified as control, intermediate AMD, or advanced AMD based on clinical presentation. 16S rRNA amplicon sequencing and standard chromatography-mass spectrometry methods were used to identify bacterial taxonomy composition and abundance of short-chain fatty acids (SCFAs) and bile acids (BAs), respectively. Genetic testing was used to investigate the frequency of 14 high-risk single nucleotide polymorphisms (SNPs) associated with AMD in the AMD cohort.

Results

Forty-three differentially abundant genera were present among the control, intermediate, and advanced groups. Taxa with known roles in immunologic pathways, such as Desulfovibrionales (q = 0.10) and Terrisporobacter (q = 1.16e-03), were in greater abundance in advanced AMD patients compared to intermediate. Advanced AMD patients had decreased abundance of 12 SCFAs, including acetate (P = 0.002), butyrate (P = 0.04), and propionate (P = 0.01), along with 12 BAs, including taurocholic acid (P = 0.02) and tauroursodeoxycholic acid (P = 0.04). Frequencies of high-risk SNPs were not significantly different between the intermediate and advanced AMD groups.

Conclusions

This pilot study identifies distinct gut microbiome compositions and metabolomic profiles associated with AMD and its stages, providing preliminary evidence of a potential link between gut microbiota and AMD pathogenesis. To validate these findings and elucidate the underlying mechanisms, future research with larger cohorts and more comprehensive sampling is strongly recommended.

Bugs got milk? Exploring the potential of lactose as a prebiotic ingredient for the human gut microbiota of lactose-tolerant individuals

Milk consumption is important to help meet daily nutrient requirements. However, lactose-present in dairy products-has been associated with digestive discomfort in individuals who are lactose intolerant or have inadequate lactase activity. Yet, a new perspective on this dietary component has emerged: its potential as a prebiotic for the lactose-tolerant population. We hypothesized that ingestion of lactose may improve the microbial community structure and metabolism of the gut microbiota from healthy adults. First, we assessed the acute impact of lactose ingestion on the gut microbiota of adults using a short-duration in vitro batch colonic model. Subsequently, we employed a long-duration in vitro dynamic multivessel colonic model to evaluate the effects of lactose chronic ingestion. In both cases, a mixture of lactose/galactose/glucose was administered in a defined proportion to mimic lactose metabolism and galactose/glucose absorption in lactose-tolerant adults. The hypothesis was confirmed, as a modulatory prebiotic effect was revealed on the microbial community structure and metabolism of the microbiota upon treatments simulating the ingestion of three doses of lactose, equivalent to half a glass, one glass, and two glasses of cow's milk. The long-duration model confirmed this potential, increasing the relative abundance of the beneficial genera Lactobacillus, Akkermansia, and Faecalibacterium, while the usually detrimental genus Clostridium decreased. Additionally, the health-promoting microbial metabolites acetate, propionate, and lactate were increased. Therefore, lactose ingestion could positively modulate the gut microbiota in healthy lactose-tolerant adults, thereby promoting gut health and shedding light on the dietary benefits of consuming milk.

Leveraging Organ-on-Chip Models to Investigate Host-Microbiota Dynamics and Targeted Therapies for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic gastrointestinal disease with drastically increasing incidence rates. Due to its multifactorial etiology, a precise investigation of the pathogenesis is extremely difficult. Although reductionist cell culture models and more complex disease models in animals have clarified the understanding of individual disease mechanisms and contributing factors of IBD in the past, it remains challenging to bridge research and clinical practice. Conventional 2D cell culture models cannot replicate complex host-microbiota interactions and stable long-term microbial culture. Further, extrapolating data from animal models to patients remains challenging due to genetic and environmental diversity leading to differences in immune responses. Human intestine organ-on-chip (OoC) models have emerged as an alternative in vitro model approach to investigate IBD. OoC models not only recapitulate the human intestinal microenvironment more accurately than 2D cultures yet may also be advantageous for the identification of important disease-driving factors and pharmacological interventions targets due to the possibility of emulating different complexities. The predispositions and biological hallmarks of IBD focusing on host-microbiota interactions at the intestinal mucosal barrier are elucidated here. Additionally, the potential of OoCs to explore microbiota-related therapies and personalized medicine for IBD treatment is discussed.

Comparative gut microbiome research through the lens of ecology: theoretical considerations and best practices

Comparative approaches in animal gut microbiome research have revealed patterns of phylosymbiosis, dietary and physiological convergences, and environment-host interactions. However, most large-scale comparative studies, especially those that are highly cited, have focused on mammals, and efforts to integrate comparative approaches with existing ecological frameworks are lacking. While mammals serve as useful model organisms, developing generalised principles of how animal gut microbiomes are shaped and how these microbiomes interact bidirectionally with host ecology and evolution requires a more complete sampling of the animal kingdom. Here, we provide an overview of what past comparative studies have taught us about the gut microbiome, and how community ecology theory may help resolve certain contradictions in comparative gut microbiome research. We explore whether certain hypotheses are supported across clades, and how the disproportionate focus on mammals has introduced potential bias into gut microbiome theory. We then introduce a methodological solution by which public gut microbiome data of understudied hosts can be compiled and analysed in a comparative context. Our aggregation and analysis of 179 studies shows that generating data sets with rich host diversity is possible with public data and that key gut microbes associated with mammals are widespread across the animal kingdom. We also show the effects that sample size and taxonomic rank have on comparative gut microbiome studies and that results of multivariate analyses can vary significantly with these two parameters. While challenges remain in developing a universal model of the animal gut microbiome, we show that existing ecological frameworks can help bring us one step closer to integrating the gut microbiome into animal ecology and evolution.

Short-chain fatty acids in Huntington's disease: Mechanisms of action and their therapeutic implications

Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor dysfunction, cognitive decline, and emotional instability, primarily resulting from the abnormal accumulation of mutant huntingtin protein. Growing research highlights the role of intestinal microbiota and their metabolites, particularly short-chain fatty acids (SCFAs), in modulating HD progression. SCFAs, including acetate, propionate, and butyrate, are produced by gut bacteria through dietary fiber fermentation and are recognized for their neuroprotective properties. Evidence suggests that SCFAs regulate neuroinflammation, neuronal communication, and metabolic functions within the central nervous system (CNS). In HD, these compounds may support neuronal health, reduce oxidative stress, and enhance blood-brain barrier (BBB) integrity. Their mechanisms of action involve binding to G-protein-coupled receptors (GPCRs) and modulating gene expression through epigenetic pathways, underscoring their therapeutic potential. This analysis examines the significance of SCFAs in HD, emphasizing the gut-brain axis and the benefits of dietary interventions aimed at modifying gut microbiota composition and promoting SCFA production. Further research into these pathways may pave the way for novel HD management strategies and improved therapeutic outcomes.

The gut microbiome and dietary metabolites in the treatment of renal cell carcinoma

The gut microbiome is interlinked with renal cell carcinoma (RCC) and its response to systemic treatment. Mounting data suggests that certain elements of the gut microbiome may correlate with improved outcomes. New generation sequencing techniques and advanced bioinformatic data curation are accelerating the investigation of specific markers and metabolites that could predict treatment response. A variety of new therapeutic strategies, such as fecal microbiota transplantation, probiotic supplements, and dietary interventions, are currently being developed to modify the gut microbiome and improve anticancer therapies in patients with RCC. This review discusses the preliminary evidence indicating the role of the microbiome in cancer treatment, the techniques and tools necessary for its proper study and some of the current forms with which the microbiome can be modulated to improve patient outcomes.

Exposure to circadian disrupting environment and high-fat diet during pregnancy and lactation alter reproductive competence and lipid profiles of liver, mammary, plasma and milk of ICR mice

This study's objective was to determine the effects of pre-pregnancy obesity induced by a high-fat diet and exposure to circadian-disrupting light-dark phase shifts on birth littler size, pup survival to 24h and growth to lactation day 12, and their relationship to maternal feeding patterns, fecal corticosterone levels, milk composition, and lipid profiles of liver, plasma, mammary gland, and milk. A 2 by 2 factorial designed experiment of female ICR mice assigned to control (CON; 10% fat) or high-fat (HF; 60% fat) and either a 12-hour light-dark (LD) cycle or a chronic jet lag model of 6-hour phase-shifts (PS) in light-dark cycle every 3 days throughout pregnancy and lactation, resulted in 4 treatment groups: CON-LD, CON-PS, HF-LD and HF-PS. HF diet increased maternal pre-pregnancy body weight and elevated milk lactose. Whereas PS reduced milk lactose within the CON diet group, and increased maternal feed intake and fecal corticosterone levels. PS exposure also affected the time of day of birth. Neither PS nor HF affected birth litter size or pup survival. Only diet impacted final litter weight, with HF greater than CON. Among the 1204 lipids detected by multiple reaction monitoring (MRM)-profiling, diet altered 67.1% in milk, 58.1% in mammary gland, 27.2% in the liver, and 10.9% in plasma, with HF increasing the carbon length of diacylglycerols in the liver and milk, and carbon length of triacylglycerols in plasma, mammary gland and milk. Although exposure to PS had no overall impact on maternal lipid profiles, interactions (P < 0.05) were found between PS and diets in the phosphatidylcholine and phosphatidylethanolanine class of lipids. Findings support that high fat diet and exposure to circadian disrupting environments impact maternal feeding behavior and stress responses as well as lipid profiles, which may relate to their negative association with maternal health and offspring development.

The role of polysaccharides in immune regulation through gut microbiota: mechanisms and implications

Polysaccharides, as complex carbohydrates, play a pivotal role in immune modulation and interactions with the gut microbiota. The diverse array of dietary polysaccharides influences gut microbial ecology, impacting immune responses, metabolism, and overall well-being. Despite their recognized benefits, there is limited understanding of the precise mechanisms by which polysaccharides modulate the immune system through the gut microbiota. A comprehensive search of Web of Science, PubMed, Google Scholar, and Embase up to May 2024 was conducted to identify relevant studies. This study employs a systematic approach to explore the interplay between polysaccharides and the gut microbiota, focusing on cytokine-mediated and short-chain fatty acid (SCFA)-mediated pathways. The findings underscore the significant role of polysaccharides in shaping the composition and function of the gut microbiota, thereby influencing immune regulation and metabolic processes. However, further research is necessary to elucidate the detailed molecular mechanisms and translate these findings into clinical applications.

The microbiota-gut-brain axis in myalgic encephalomyelitis/chronic fatigue syndrome: a narrative review of an emerging field

The intricate relationship between gut microbiota and the brain has emerged as a pivotal area of research, particularly in understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). This complex condition is characterized by debilitating fatigue, cognitive dysfunction, and a wide array of systemic manifestations, posing significant challenges for diagnosis and treatment. Recent studies highlight the microbiota-gut-brain axis as a crucial pathway in ME/CFS pathophysiology, suggesting that alterations in gut microbial composition may impact immune responses, neurochemical signaling, and neuronal health. This narrative review systematically explores English-language scholarly articles from January 1995 to January 2025, utilizing databases such as PubMed, Scopus, and Web of Science. The findings underscore the potential for targeted therapeutic interventions aimed at correcting gut dysbiosis. As research progresses, a deeper understanding of the microbiota-gut-brain connection could lead to innovative approaches for managing ME/CFS, ultimately enhancing the quality of life for affected individuals.

Effect of Management System on Fecal Microbiota in Arabian Horses: Preliminary Results

The gut microbiota plays a basic role in maintaining the psychophysical health and well-being of horses. Understanding the complex interactions among microbial communities in relation to age, management, and health is a topic of growing interest. The equine microbiota, given its complexity, is subject to variations caused by internal or external stressors that can lead to metabolic problems and pathologies, i.e., obesity and laminitis. The aim of this study was to characterize the fecal microbiota of 12 purebred Arabian horses and to compare the microbial communities in two distinct management systems (Group 1 = box 22 h/day + paddock 2 h/day and Group 2 = paddock 24 h). Fecal samples were analyzed using high-throughput sequencing of 16S rRNA V3-V4 amplicons. The microbiota was predominantly composed of Firmicutes (32-53%) and Bacteroidetes (32-47.8%), with Ruminococcaceae emerging as the most prevalent bacterial family (10.9-24%). Comparisons of alpha and beta diversity revealed no statistically significant differences between the groups based on different management systems. This preliminary characterization contributes valuable data for understanding the equine fecal microbiota and lays the groundwork for future studies on the relationship among intestinal microbiota and equine health, performance, and management strategies.

Oxidative Stress, Gut Microbiota, and Extracellular Vesicles: Interconnected Pathways and Therapeutic Potentials

Oxidative stress (OS) and gut microbiota are crucial factors influencing human health, each playing a significant role in the development and progression of chronic diseases. This review provides a comprehensive analysis of the complex interplay between these two factors, focusing on how an imbalance between reactive oxygen species (ROS) and antioxidants leads to OS, disrupting cellular homeostasis and contributing to a range of conditions, including metabolic disorders, cardiovascular diseases, neurological diseases, and cancer. The gut microbiota, a diverse community of microorganisms residing in the gastrointestinal tract, is essential for regulating immune responses, metabolic pathways, and overall health. Dysbiosis, an imbalance in the gut microbiota composition, is closely associated with chronic inflammation, metabolic dysfunction, and various diseases. This review highlights how the gut microbiota influences and is influenced by OS, complicating the pathophysiology of many conditions. Furthermore, emerging evidence has identified extracellular vesicles (EVs) as critical facilitators of cellular crosstalk between the OS and gut microbiota. EVs also play a crucial role in signaling between the gut microbiota and host tissues, modulating immune responses, inflammation, and metabolic processes. The signaling function of EVs holds promise for the development of targeted therapies aimed at restoring microbial balance and mitigating OS. Personalized therapeutic approaches, including probiotics, antioxidants, and fecal microbiota transplantation-based strategies, can be used to address OS-related diseases and improve health outcomes. Nonetheless, further research is needed to study the molecular mechanisms underlying these interactions and the potential of innovative interventions to offer novel strategies for managing OS-related diseases and enhancing overall human health.

Metabolic Profiling of Fermented Products of the Ethanolic Extract of Acanthopanax sessiliflorus Fruit and Evaluation of Its Immune Enhancement Effect in RAW 264.7 Macrophages and BV2 Microglia

In this study, we sought to evaluate the potential availability of 30% ethanol extract of Acanthopanax sessiliflorus fruit (ASE) as a prebiotic and compare the immune enhancement effect of ASE and its fermented products, which were fermented with three probiotic bacteria, namely, Lactobacillus plantarum (ASE-LPF), Streptococcus thermophilus (ASE-STF), and Lactobacillus helveticus (ASE-LHF). RAW264.7 and BV2 cells were treated with various concentrations of ASE and its fermented products. The level of nitric oxide was evaluated using a Griess reagent, and the levels of inflammatory cytokines were determined through an enzyme-linked immunosorbent assay. Western blot analysis was employed to determine the expression of various proteins related to immune responses. Our results show that fermentation with ASE significantly improved the probiotic growth of S. thermophilus and L. helveticus. Compared with ASE, treatment with only ASE-LHF increased the level of nitric oxide. Compared with ASE, treatment with ASE-LHF augmented the expression of inducible nitric oxide synthase, cyclooxygenase-2, and the production of inflammatory cytokines. It was confirmed that these enhancement effects were due to the activation of the nuclear factor kappa B and extracellular signal-regulated kinase mitogen-activated protein kinase signaling pathways. Additionally, secondary metabolite profiling of ASE and its fermented products was performed using UPLC-QTOF/MS to identify ASE's promising compounds. Through metabolomic analysis, 23 metabolites showing significant differences between ASE and its fermented products were compared. Therefore, this study demonstrates the possibility of ASE-LHF as a potential material for immune-enhancing agents.

Idiopathic epilepsy in dogs is associated with dysbiotic faecal microbiota

BACKGROUND

The gut microbiota plays a crucial role in modulating various physiological and pathological processes through its metabolites, including short-chain fatty acids (SCFA), which impact immune system development, gastrointestinal health, and brain functions via the gut-brain axis. Dysbiosis, an imbalance in gut microbiota composition, has been linked to neuroinflammatory and neurodegenerative conditions, including epilepsy. In dogs, idiopathic epilepsy has been hypothesized to be influenced by gut microbiota composition, although studies on this association are limited and show inconsistent results. Here, we compared the faecal microbiota of idiopathic epileptic drug-naïve dogs and healthy controls. To this aim, we recruited 19 idiopathic epileptic dogs and 17 healthy controls which met stringent inclusion criteria and characterized their faecal microbiome by 16 S rRNA sequencing.

RESULTS

No significant differences were observed between the two groups regarding age, breed, body condition score, diet, or reproductive status, though males were significantly overrepresented in the idiopathic epileptic group. Epileptic dogs showed a marked reduction in bacterial richness and a trend towards lower evenness (α-diversity) compared to healthy controls, while no differences in community composition (β-diversity) were observed between the two groups. Moreover, a decrease in SCFA-producing bacteria, namely Faecalibacterium, Prevotella, and Blautia, was observed alongside an increase in Escherichia coli, Clostridium perfringens, and Bacteroides in epileptic dogs.

CONCLUSIONS

Idiopathic epileptic dogs exhibit dysbiosis, with reduced bacterial diversity, loss of beneficial genera, and overgrowth of opportunistic pathogens. These alterations in microbiota diversity and composition may contribute to epilepsy via the gut-brain axis, highlighting the need for further research to explore dietary or probiotic interventions targeting gut microbiota modulation as adjunctive therapies for managing epilepsy in dogs.

Short-term alterations in dietary amino acids override host genetic susceptibility and reveal mechanisms of Salmonella Typhimurium small intestine colonization

In addition to individual genetics, environmental factors (e.g., dietary changes) may influence host susceptibility to gastrointestinal infection through unknown mechanisms. Herein, we developed a model in which CBA/J mice, a genetically resistant strain that tolerates intestinal colonization by the enteric pathogen Salmonella Typhimurium (S. Tm), rapidly succumb to infection after exposure to a diet rich in L-amino acids (AA). In mice, S. Tm-gastroenteritis is restricted to the large intestine (cecum), limiting their use to understand S. Tm small intestine (ileum) colonization, a feature of human Salmonellosis. Surprisingly, CBA mice fed AA diet developed ileitis with enhanced S. Tm ileal colonization. Using germ-free mice and ileal-fecal slurry transplant, we found diet-mediated S. Tm ileal expansion to be microbiota-dependent. Mechanistically, S. Tm relied on Fructosyl-asparagine utilization to expand in the ileum during infection. We demonstrate how AA diet overrides host genetics by altering the gut microbiota's ability to prevent S. Tm ileal colonization.

Role of Gut Microbiota in the Development of Some Autoimmune Diseases

The gut microbiota is crucial for maintaining the homeostasis and function of the immune system. It interacts with the host's immune system through various mechanisms, including promoting immune tolerance, affecting the differentiation and function of immune cells, and participating in the metabolism of immune regulatory substances. The disruption of the gut microbiome may lead to impaired mucosal barrier function, allowing bacteria and their metabolites to invade into the host, activate or interfere with the immune system, and potentially trigger or exacerbate autoimmune responses. Understanding the relationship between the microbiome and autoimmune diseases may help develop new treatment strategies. This article reviewed the recent progresses of microbiome involved in the occurrence and development of some autoimmune diseases and the treatment methods based on regulation of the microbiome, highlighted the key role of microbiome in autoimmune diseases.

Optimizing chronic kidney disease management: The potential of a multi-strain probiotic formulation

Chronic kidney disease (CKD), which represents a significant global health concern, is characterized by a gradual decline in kidney function, leading to complications such as electrolyte imbalance, cardiovascular disease, and immune dysfunction. Standard CKD management includes dietary modifications, ketoanalogues supplementation, blood pressure and blood glucose control, hydration maintenance, and treatment of the underlying causes. Emerging evidence has indicated a significant role of the gut microbiota in CKD, and that dysbiosis of the gut microbiota contributes to the progression of CKD towards end-stage renal disease. Probiotics and prebiotics have recently garnered attention owing to their potential to enhance gastrointestinal health and well-being by restoring the balance of the gut microbiota. Specific probiotic strains, including Lactobacillus and Bifidobacterium, promote beneficial bacterial growth, suppress harmful bacteria, and exert anti-inflammatory, antihypertensive, and antidiabetic effects. The combination of Streptococcus thermophilus, Lactobacillus acidophilus, Bifidobacterium longum, and Bacillus coagulans has demonstrated potential as a therapeutic formulation for CKD management in various studies, highlighting its promise in treating CKD; however, supporting evidence remains limited, making it crucial to conduct further investigations to determine the specific effects of different probiotic formulations on outcomes in patients with CKD.

The Role of Short-Chain Fatty Acids in Metabolic Dysfunction-Associated Steatotic Liver Disease and Other Metabolic Diseases

With its increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a major global public health concern over the past few decades. Growing evidence has proposed the microbiota-derived metabolites short-chain fatty acids (SCFAs) as a potential factor in the pathophysiology of MASLD and related metabolic conditions, such as obesity and type 2 diabetes mellitus (T2DM). By influencing key pathways involved in energy homeostasis, insulin sensitivity, and inflammation, SCFAs play an important role in gut microbiota composition, intestinal barrier function, immune modulation, and direct metabolic signaling. Furthermore, recent animal and human studies on therapeutic strategies targeting SCFAs demonstrate their potential for treating these metabolic disorders.

Medication-resistant epilepsy is associated with a unique gut microbiota signature

OBJECTIVE

Dysfunction of the microbiota-gut-brain axis is emerging as a new pathogenic mechanism in epilepsy, potentially impacting on medication response and disease outcome. We investigated the composition of the gut microbiota in a cohort of medication-resistant (MR) and medication-sensitive (MS) pediatric patients with epilepsy.

METHODS

Children with epilepsy of genetic and presumed genetic etiologies were evaluated clinically and subgrouped into MR and MS. Age-matched healthy controls (HCs) were also recruited. A food diary was used to evaluate nutritional habits, and the Rome IV questionnaire was used to record gastrointestinal symptoms. The microbiota composition was assessed in stool samples through 16S rRNA. α-Diversity (AD) and β-diversity (BD) were calculated, and differential abundance analysis was performed using linear multivariable models (significance: p.adj < .05).

RESULTS

Forty-one patients (MR:MS = 20:21) with a mean age of 7.2 years (±4.6 SD) and 27 age-matched HCs were recruited. No significant differences in AD were found when comparing patients and HCs. Significant positive correlation was found between AD and age (Chao1 p.adj = .0004, Shannon p.adj = .0004, Simpson p.adj = .0028). BD depicted a different bacterial profile in the epilepsy groups compared to HCs (MS vs. HC: Bray-Curtis F = 1.783, p = .001; Jaccard F = 1.24, p = .001; MR vs. HC: Bray-Curtis F = 2.24, p = .001; Jaccard F = 1.364, p = .001). At the genus level, the epilepsy groups were characterized by a significant increase in Hungatella (MS vs. HC: +4.95 log2 change; MR vs. HC: +6.72 log2 change); the [Eubacterium] siraeum group changed between the MR and MS subgroups.

SIGNIFICANCE

Epileptic patients display unique gut metagenomic signatures compared to HCs. Moreover, a different ratio of the butyrate-producing [Eubacterium] siraeum group suggests dissimilarities between patients based on the response to antiseizure medications.

Sexual Dimorphism in Cardiometabolic Diseases: From Development to Senescence and Therapeutic Approaches

The global incidence and prevalence of cardiometabolic disorders have risen significantly in recent years. Although lifestyle choices in adulthood play a crucial role in the development of these conditions, it is well established that events occurring early in life can have an important effect. Recent research on cardiometabolic diseases has highlighted the influence of sexual dimorphism on risk factors, underlying mechanisms, and response to therapies. In this narrative review, we summarize the current understanding of sexual dimorphism in cardiovascular and metabolic diseases in the general population and within the framework of the Developmental Origins of Health and Disease (DOHaD) concept. We explore key risk factors and mechanisms, including the influence of genetic and epigenetic factors, placental and embryonic development, maternal nutrition, sex hormones, energy metabolism, microbiota, oxidative stress, cell death, inflammation, endothelial dysfunction, circadian rhythm, and lifestyle factors. Finally, we discuss some of the main therapeutic approaches, responses to which may be influenced by sexual dimorphism, such as antihypertensive and cardiovascular treatments, oxidative stress management, nutrition, cell therapies, and hormone replacement therapy.

Almond snacking modulates gut microbiome and metabolome in association with improved cardiometabolic and inflammatory markers

Western-style dietary patterns have been linked with obesity and associated metabolic disorders and gut dysbiosis, whereas prudent dietary and snacking choices mitigate these predispositions. Using a multi-omics approach, we investigated how almond snacking counters gut imbalances linked to adiposity and an average American Diet (AAD). Fifteen adults with overweight or obesity underwent a randomized, crossover-controlled feeding trial comparing a 4-week AAD with a similar isocaloric diet supplemented with 42.5 g/day of almonds (ALD). Almond snacking increases functional gut microbes, including Faecalibacterium prausnitzii, while suppressing opportunistic pathogens, thereby favorably modulating gut microecological niches through symbiotic and microbe-metabolite interactions. Moreover, ALD elevates health-beneficial monosaccharides and fosters bacterial consumption of amino acids, owing to enhanced microbial homeostasis. Additionally, ALD enhances metabolic homeostasis through a ketosis-like effect, reduces inflammation, and improves satiety-regulating hormones. The findings suggest that prudent dietary choices, such as almond snacking, promote gut microbial homeostasis while modulating immune metabolic state.

Sleep duration as a mediator in the association between dietary intake of live microbes and insulin resistance: a cross-sectional study

BACKGROUND

Insulin resistance and associated metabolic health symptoms remain a primary global health concern. In addition to healthy dietary and nutritional programs, sleep duration is closely related to and has been linked to healthy metabolism. This study aimed to determine the link between insulin resistance and sleep duration and the dietary intake of live microbes.

METHODS

Data were collected from 15,927 participants in the National Health and Nutrition Examination Survey database from 2005 to 2018; this sample is equivalent to 209,316,590 individuals in the United States. The participants were categorized according to their consumption of foods containing live microbes: low, medium, high, and medium-high. The relationship between diets containing live microbes and the triglyceride-glucose index was analysed using a weighted multivariate linear regression model with a multistage sampling approach. The individuals were deemed to have insulin resistance if their homeostatic model assessment score for insulin resistance was ≥ 2. The relationship between diets containing live microbes and insulin resistance status was assessed using weighted multivariate logistic regression analyses. The mediating role of sleep duration on the relationship between diets containing live microbes and the triglyceride-glucose index was also examined.

RESULTS

After accounting for potential confounders, diets containing live microbes at medium and medium-high levels were significantly associated with a reduced triglyceride-glucose index. The medium and medium-high levels of live microbial intake were also associated with a lower risk of insulin resistance. Within the 6-9 hours' sleep duration range, the indirect effect of medium and medium-high levels of live microbes on the triglyceride-glucose index was observed, accounting for 2.95% and 6.08% of the overall change, respectively.

CONCLUSIONS

This study suggests an association between a diet rich in medium and medium-high viable microbes, lower triglyceride-glucose index values, and a reduced risk of developing insulin resistance. Additionally, a sleep duration of 6-9 h may mediate this association.

MAGs-based genomic comparison of gut significantly enriched microbes in obese individuals pre- and post-bariatric surgery across diverse locations

Introduction

Obesity, a pressing global health issue, is intricately associated with distinct gut microbiota profiles. Bariatric surgeries, such as Laparoscopic Sleeve Gastrectomy (LSG), Sleeve Gastrectomy (SG), and Roux-en-Y Gastric Bypass (RYGB), induce substantial weight loss and reshape gut microbiota composition and functionality, yet their comparative impacts remain underexplored.

Methods

This study integrated four published metagenomic datasets, encompassing 500 samples, and employed a unified bioinformatics workflow for analysis. We assessed gut microbiota α-diversity, identified species biomarkers using three differential analysis approaches, and constructed high-quality Metagenome-Assembled Genomes (MAGs). Comparative genomic, functional profiling and KEGG pathway analyses were performed, alongside estimation of microbial growth rates via Peak-to-Trough Ratios (PTRs).

Results

RYGB exhibited the most pronounced enhancement of gut microbiota α-diversity compared to LSG and SG. Cross-cohort analysis identified 39 species biomarkers: 27 enriched in the non-obesity group (NonOB_Enrich) and 12 in the obesity group (OB_Enrich). Among the MAGs, 177 were NonOB_Enrich and 14 were OB_Enrich. NonOB_Enrich MAGs displayed enriched carbohydrate degradation profiles (e.g., GH105, GH2, GH23, GH43, and GT0 families) and higher gene diversity in fatty acid biosynthesis and secondary metabolite pathways, alongside significant enrichment in amino acid metabolism (KEGG analysis). Post-surgery, Akkermansia muciniphila and Bacteroides uniformis showed elevated growth rates based on PTRs.

Discussion

These findings underscore RYGB's superior impact on gut microbiota diversity and highlight distinct microbial functional adaptations linked to weight loss, offering insights for targeted therapeutic strategies.

Nutritional Interventions in Amyotrophic Lateral Sclerosis: From Ketogenic Diet and Neuroprotective Nutrients to the Microbiota-Gut-Brain Axis Regulation

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disease with significant challenges in diagnosis and treatment. Recent research has highlighted the complex nature of ALS, encompassing behavioral impairments in addition to its neurological manifestations. While several medications have been approved to slow disease progression, ongoing research is focused on identifying new therapeutic targets. The current review focuses on emerging therapeutic strategies and personalized approaches aimed at improving patient outcomes. Recent advancements highlight the importance of targeting additional pathways such as mitochondrial dysfunction and neuroinflammation to develop more effective treatments. Personalized medicine, including genetic testing and biomarkers, is proving valuable in stratifying patients and tailoring treatment options. Complementary therapies, such as nutritional interventions like the ketogenic diet and microbiome modulation, also show promise. This review emphasizes the need for a multidisciplinary approach that integrates early diagnosis, targeted treatments, and supportive care to address the multisystemic nature of ALS and improve the quality of life for patients.

Assessing the gut microbiota composition in older adults: connections to physical activity and healthy ageing

The composition and functionality of the gut microbiota (GM) changes throughout the life course. As we move into older age, it starts to shift towards a less healthy one, which may lead to an imbalance in the GM community. Strategies that can reverse age-related dysbiosis are an important part of healthy aging. Little is known about the GM composition of older adults with different physical activity (PA) levels and whether it might contribute to healthy ageing. The aim of this study was to compare the GM composition of older adults with different PA levels and assess if it is associated with healthy ageing. 101 participants aged between 65-85 years undertook anthropometric measures, a 6-min walking test, wore an accelerometer for 7 days and provided a faecal sample. Faecal GM composition was analysed using 16S rRNA sequencing. We found that those who fulfilled the WHO/UK PA recommendations had higher relative abundance of several health-related bacteria such as Lactobacillus, F. prausnitzii and Roseburia intestinalis and lower abundance of disease-associated bacteria such as D.piger or Enterobacterales when compared to those who did not reach PA recommendations. These findings suggest that PA might improve the GM composition and has the potential to, at least partially, revert age-associated dysbiosis and promote healthy ageing.

Evaluating the protective effects of the Toll-like receptor (TLR) 21 ligand, CpG ODN, against necrotic enteritis in broiler chickens

Necrotic enteritis (NE), caused by Clostridium perfringens (C. perfringens), presents a challenge to the global broiler industry. Evidence suggests that Toll-like receptor (TLR) ligands can enhance the immune responses in chickens and protect them against infectious diseases. This study investigated the protective effects of TLR21 ligand class B CpG oligonucleotides (ODN) against NE in broiler chickens. On day 21 of age, chickens were injected with 50 or 100 μg CpG intramuscularly, and one group was injected with 50 μg CpG followed by a booster dose on day 22. Subsequently, birds were orally challenged with C. perfringens twice daily for three days, starting on day 22. On day 22, intestinal samples were collected for gene expression analysis. On day 25, all birds were euthanized, intestinal lesions were scored, and tissue samples were collected from the intestine for gene expression analysis, lymphocyte subset determination, and histomorphological analysis. Cecal contents were also collected for microbiome analysis. The results demonstrated that CpG pre-treatment, either at a single dose of 100 μg or two doses of 50 μg per bird, reduced lesion scores compared to the positive control. C. perfringens infection increased crypt depth in both the jejunum and ileum in the positive control group compared to both the CpG-treated group. At 22 days of age, CpG administration at doses of 100 μg per bird enhanced expression of TLR21, interleukin (IL)-2, CXCL8, IL-10, and interferon (IFN)-γ mRNA transcripts in both the jejunum and ileum. Additionally, at 25 days of age, the group pretreated with two doses of 50 μg of CpG per bird showed increased expression of all cytokines in both the jejunum and ileum compared to the control groups. The percentage of intestinal lymphocytes was not affected by CpG pre-treatment. However, CpG pretreatment at doses of 100 μg resulted in a higher abundance of the members of families Lactobacillaceae and Bacteroidaceae, which are crucial for maintaining gut health. In conclusion, our findings suggest that pretreatment of chickens with intramuscular administration of CpG may be effective in maintaining gut health during C. perfringens infection.

Effect of Lactiplantibacillus plantarum N-1 and isomaltose-oligosaccharide on promoting growth performance and modulating the gastrointestinal microbiota in newborn Hu sheep

BACKGROUND

Diarrhea is usually observed in newborn Hu lambs, while severe diarrhea may lead to the stunted growth and even death in lambs, necessitating the common practice of antibiotic administration to newborns. In order to explore the application of the effective probiotics and/or prebiotic treatment in animal feed to lessen the recline on antibiotics, 27 newborn of Hu lambs were equally allocated into three groups: control group (Con), probiotics group (Pro) receiving Lactiplantibacillus plantarum N-1 (LPN-1), and synbiotics group (Syn) receiving LPN-1 combined with isomaltose-oligosaccharide (IMO), and raised till 60 days of age.

RESULTS

Compared with the Con, the incidence of severe diarrhea was lower in both two treatment groups, accompanied by a significant reduction in terramycin administration frequency (P < 0.05). The daily feed intake in newborns significantly increased after probiotics or synbiotics treatment (P < 0.05), leading to the substantial increment in average daily gain by 48.28% and heart girth (P < 0.05), as well as enhancements in height (P < 0.01) at 60 days of the age in synbiotics treatment group. Applying probiotics and synbiotics exhibited the enhanced rumen weight (P < 0.05), and synbiotics further promoted the spleen development (P < 0.05). The inclusion of probiotics and synbiotics significantly modified the gut microbial composition of Hu lambs (P < 0.01), with an increase in Butyrivibrio proteoclasticus and Pseudoruminococcus massiliensis, which were associated with starch and sucrose metabolism. Additionally, the Syn group exhibited an upsurge in the number of species associated with amino acid metabolism and cellulolysis, as well as the raised short-chain fatty acids levels in the newborn gut (P < 0.05).

CONCLUSIONS

This study demonstrated that LPN-1 and IMO had an enhanced effect to improve the growth performance and decrease the reliance on antibiotics by promoting the feed intake, balancing the gut microbiota and increasing the short-chain fatty acids content in Hu lambs.

Probiotics and Plant-Based Foods as Preventive Agents of Urinary Tract Infection: A Narrative Review of Possible Mechanisms Related to Health

Urinary tract infections (UTIs) are a prevalent global health issue, often requiring antibiotic treatment, which contributes to antimicrobial resistance. This narrative review explores the potential of probiotics and plant-based foods as alternative or complementary preventive strategies against UTIs. Fermented foods, such as yogurt, kefir, and kombucha, contain probiotic strains that can modulate the gut and urogenital microbiota, enhancing resistance to uropathogens. Likewise, plant-based foods, including cranberry, garlic, bearberry, juniper, and nettle, possess bioactive compounds with antimicrobial, anti-inflammatory, and diuretic properties. Laboratory and clinical studies suggest that these natural interventions may reduce the incidence of UTIs by inhibiting pathogen adhesion, modulating immune responses, and promoting urinary tract health. However, despite promising findings, inconsistencies in study methodologies, dosage standardization, and long-term efficacy warrant further investigation. Future research should focus on optimizing probiotic formulations, standardizing plant-based supplement dosages, and assessing potential food-drug interactions to establish evidence-based guidelines for UTI prevention.

Gut Metagenome Reveals the Microbiome Signatures in Tibetan and Black Pigs

The harsh conditions of the Qinghai-Tibet Plateau pose significant physiological challenges to local fauna, often resulting in gastrointestinal disorders. However, Tibetan pigs have exhibited remarkable adaptability to the high-altitude stress of the Tibetan Plateau, a phenomenon that remains not fully understood in terms of their gastrointestinal microbiota. This study collected 57 gastrointestinal tract samples from Tibetan pigs (n = 6) and plain black pigs (n = 6) with comparable genetic backgrounds. Samples from the stomach, jejunum, cecum, colon, and rectum, underwent comprehensive metagenomic analysis to elucidate the gut microbiota-related adaptive mechanisms in Tibetan pigs to the extreme high-altitude environment. A predominance of Pseudomonadota was observed within gut microbiome of Tibetan pigs. Significant differences in the microbial composition were also identified across the tested gastrointestinal segments, with 18 genera and 141 species exhibiting differential abundance. Genera such as Bifidobacterium, Megasphaera, Fusobacterium, and Mitsuokella were significantly more abundant in Tibetan pigs than in their lowland counterparts, suggesting specialized adaptations. Network analysis found greater complexity and modularity in the microbiota of Tibetan pigs compared to black pigs, indicating enhanced ecological stability and adaptability. Functional analysis revealed that the Tibetan pig microbiota was particularly enriched with bacterial species involved in metabolic pathways for propionate and butyrate, key short-chain fatty acids that support energy provision under low-oxygen conditions. The enzymatic profiles of Tibetan pigs, characterized by elevated levels of 4-hydroxybutyrate dehydrogenase and glutaconyl-CoA decarboxylase, highlighted a robust fatty acid metabolism and enhanced tricarboxylic acid cycle activity. In contrast, the gut microbiome of plain black pigs showed a reliance on the succinate pathway, with a reduced butyrate metabolism and lower metabolic flexibility. Taken together, these results demonstrate the crucial role of the gastrointestinal microbiota in the adaptation of Tibetan pigs to high-altitude environments by optimizing carbohydrate metabolism and short-chain fatty acid production for efficient energy utilization. This study not only highlights the metabolic benefits conferred by the gut microbiota of Tibetan pigs in extreme environments, but also advances our understanding of the adaptive gastrointestinal mechanisms in plateau-dwelling animals. These insights lay the foundation for exploring metabolic interventions to support health and performance in high-altitude conditions.

Direct and indirect effects of pesticide exposure on the gut microbiota of a farmland raptor

Recent studies in humans have shown that certain pesticides could affect the composition and functions of the gut microbiota, an essential modulator of vertebrate physiology, leading to potential dysbiosis. However, this relationship remains largely unknown in wild birds despite the implications of pesticides in the current decline of farmland species. The present study sought to fill this gap by providing data on the association between pesticide concentrations in blood and gut microbiota characteristics in relation to individual traits in a farmland raptor, the Montagu's harrier (Circus pygargus). Results showed that females with higher body condition and higher pesticide load exhibited greater gut bacterial richness and diversity, while the relationship was opposite in males with higher body condition. In terms of taxonomic composition, Proteobacteria emerged as the dominant phylum across all nestlings. Differences in the abundance of specific phyla and genera were observed according to pesticide load, with higher levels of Bacteroidota and Leifsonia, but lower levels of Bulkholderia, in nestlings with higher pesticide concentrations in their blood. This study highlights differences in microbiota and contamination by several pesticides according to the phenotypic characteristics of a wild raptor, and shows that farmland birds can represent relevant biosentinels for assessing the health/proper functioning of ecosystems (One Health approach).

Fermented Lignan-Enriched Soy Beverage Ameliorates the Metabolic Effects of a High-Fat Diet on Female Mice

Fermented vegetable beverages have potential beneficial effects on the health associated with the production of bioactive flavonoids and lignans by selected bacterial strains. Here, we studied the effects of a soy beverage and a soy beverage fermented by Bifidobacterium pseudocatenulatum INIA P815, both supplemented with lignan extracts, in a female mouse model on a high-fat diet followed for 16 weeks. The high-fat diet induced an increase in adipose tissue and plasma cholesterol as well as modified the fecal microbiota. Mice groups receiving any of the beverages showed a reduction in the mean area of ovarian fat tissue adipocytes and exhibited bioactive flavonoids and lignans in plasma and tissues, accompanied by a higher antioxidant activity in plasma. The group of mice subjected to the fermented beverage also demonstrated a lower increase in plasma cholesterol levels, an increase in short-chain fatty acid production, and higher levels of daidzein, genistein, enterolignans, and herbacetin in the plasma and organs. Moreover, the fertility of the mice that received the fermented beverage was also enhanced, resulting in a higher percentage of blastocysts per female mouse. Therefore, the consumption of the beverage fermented by B. pseudocatenulatum INIA P815 could be favoring the health of mice by ameliorating, to some extent, the effects of a high-fat diet.

High abundance of lactobacilli in the gut microbiome of honey bees during winter

Honey bee gut microbiota play specific roles in promoting host growth and physiology by regulating the immune system, behavior, metabolism, and neurological processes. While the gut microbiota of honey bee queens, workers, and larvae has been extensively studied, less is known about the composition of gut microbiota in the winter worker bees. This study investigates the dynamics of the gut microbiota in overwintering adult worker bees, focusing on two commercial bee strains: Bolton™ bees and Mann Lake™ bees. These Apis mellifera strains were investigated under different storage conditions (indoor storage at 6 °C and outdoor storage in natural conditions) during the winter months (October, November, and December). Utilizing 16S rRNA gene amplicon sequencing, we characterized the microbial composition of the whole gut. We observed the Lactobacilli dominated in all the overwintering honey bee guts with a significantly higher abundance of unclassified Lactobacillus species in November, while Lactobacillus apis showed significantly higher abundance in October. Bolton bees exhibited significantly higher abundance levels of Bartonella (denoted as uncultured) and Bifidobacterium, along with an unexpected presence of Wolbachia. In contrast, Mann Lake bees demonstrated an increased abundance of Commensalibacter. Our results suggest that Shannon diversity is influenced by the month rather than by the bee strain or storage conditions. We also found significant differences in Bray Curtis diversity index by month. Overall, taxonomical abundance was not affected by whether the hives were stored outside or in constant temperature indoor storage. However, various bacterial species showed differences in abundance across different months, with slight variations observed between bee strains. Given the potential benefits of the honey bee gut microbiome for health and nutrition, our data suggests that the genus Lactobacillus may play a significant role in bee health during winter and overwintering storage.

Carnosic acid reduces lipid content, enhances gut health, and modulates microbiota composition and metabolism in diet-induced obese mice

Carnosic acid (CA) is a bioactive phenolic diterperne compound found in sage and rosemary. The present study investigated the beneficial effects of CA (50 and 100 mg per kg bw) in diet-induced obese mice and the underlying mechanisms of action. After the intervention, the physiology, lipid metabolism, and tissue morphology, as well as the inflammation, gut microbiota, and metabolomics in the colon were measured. We found that CA improved the composition and metabolism of the gut microbiota in obese mice, with Akkermansia being the dominant bacterium negatively correlated with obesity and various fecal metabolites. Regarding the intestinal barrier function, CA promoted the expression of tight junction proteins and inhibited the TLR4/MyD88/NF-κB signaling pathway in obese mice to alleviate colonic inflammation. These results suggest that CA improved multiple aspects of gut health in diet-induced obesity in mice, providing a scientific basis for future clinical studies in humans.

Gerobiotics: Exploring the Potential and Limitations of Repurposing Probiotics in Addressing Aging Hallmarks and Chronic Diseases

As unhealthy aging continues to rise globally, there is a pressing need for effective strategies to promote healthy aging, extend health span, and address aging-related complications. Gerobiotics, an emerging concept in geroscience, offers a novel approach to repurposing selective probiotics, postbiotics, and parabiotics to modulate key aging processes and enhance systemic health. This review explores recent advancements in gerobiotics research, focusing on their role in targeting aging hallmarks, regulating longevity-associated pathways, and reducing risks of multiple age-related chronic conditions. Despite their promise, significant challenges remain, including optimizing formulations, ensuring safety and efficacy across diverse populations, and achieving successful clinical translation. Addressing these gaps through rigorous research, well-designed clinical trials, and advanced biotechnologies can establish gerobiotics as a transformative intervention for healthy aging and chronic disease prevention.

Effects of N-Carbamylglutamate supplementation on cecal morphology, microbiota composition, and short-chain fatty acids contents of broiler breeder roosters

The objective of this study was to assess the effects of N-Carbamylglutamate (NCG) supplementation on cecal morphology, microbiota composition, and short-chain fatty acids (SCFAs) contents in broiler breeder roosters. A total of 72 11-week-old Zhuanghe Dagu broiler breeder roosters with a similar initial body weight (1.53 ± 0.06 kg) were randomly allocated into two groups. Each group had 3 replicates with 12 birds per replicate. The experimental period lasted 42 days. All birds underwent the same production practices, except for the dietary conditions. It was found that an increase in cecal muscularis thickness and villi epithelium thickness. The NCG supplementation was found to have regulatory effects on the composition of cecal microbiota. Additionally, the study observed an increase in the content of butyric acid in the cecum of broiler breeder roosters fed with the NCG-containing control diet compared to those fed with the basal diet. Spearman correlation analysis showed that the variation of cecal microbiota was closely related to the production of butyric acid as well as the improvement of muscularis and villi epithelium thickness in cecum. The increase of butyric acid content in cecum was positively correlated with the improvement of cecal muscularis and villi epithelium thickness. In conclusion, the findings of this study indicate that dietary supplementation of NCG in broiler breeder roosters can positively influence cecal morphology, microbiota composition, and butyric production.

Molecular mechanisms and therapeutic strategies of gut microbiota modulation in Sarcopenia (Review)

Sarcopenia is an age-related disease that is characterized by a decline in muscle mass and function with significant epidemiological and clinical implications. In recent years, gut microbiota has gained attention as an important regulatory factor in human health. To the best of our knowledge, this is the first study to introduce the definition and epidemiological background of sarcopenia and analyze the potential impact of the gut microbiota on muscle metabolism and growth, including aspects such as gut microbiota metabolites, muscle protein synthesis and energy metabolism. Additionally, this article summarizes the current research progress in gut microbiota interventions for the treatment of sarcopenia, such as probiotics, prebiotics and fecal microbiota transplantation and discusses future research directions and potential therapeutic strategies.

Microbiome-based therapeutics for ocular diseases

The relationship between the gut microbiome and ocular health has garnered increasing attention within the scientific community. Recent research has focused on the gut-eye axis, examining whether imbalances within the gut microbiome can influence the development, progression and severity of ocular diseases, including dry eye disease, uveitis, and glaucoma. Dysbiosis within the gut microbiome is linked to immune dysregulation, chronic inflammation, and epithelial barrier dysfunction, all of which contribute to ocular pathology. This review synthesises current evidence on these associations, exploring how gut microbiome alterations drive disease mechanisms. Furthermore, it examines the therapeutic potential of microbiome-targeted interventions, including antibiotics, prebiotics, probiotics, and faecal microbiota transplantation, all of which aim to restore microbial balance and modulate immune responses. As the prevalence of these conditions continues to rise, a deeper understanding of the gut-eye axis may facilitate the development of novel, targeted therapies to address unmet needs in the management of ocular diseases.

A possible association between low MBL/lectin pathway functionality and microbiota dysbiosis in endometriosis patients

AIMS

Endometriosis (EM) is a chronic inflammatory disorder with multifactorial etiologies (i.e., genetics and environmental factors, hormonal and immunological changes, and microbiome alterations). The complement system is one of the most frequently dysregulated pathways in EM. Mannose-binding lectin (MBL), a carbohydrate pattern recognition molecule, is the first described recognition subcomponent of the complement lectin pathway (LP). Here, we unveiled the interplay among MBL polymorphisms, plasma levels, LP functionality, and microbiota as potential contributors to EM pathogenesis.

MATERIALS AND METHODS

A cohort of 38 EM patients and 20 healthy controls was enrolled, and the levels and functionality of the LP were assessed via ELISA. MBL genetic variants and the endometrial and vaginal microbiome were investigated and correlated.

KEY FINDINGS

High MBL levels were related to the disease severity, although not accountable for the MBL2 genotype. MBL and MASP-2 were present in the uterine mucosa but appeared to have no activity at the endometriotic lesion. EM patients with LP functional deficit displayed pathogenic bacterial species more frequently in the endometrial microbiome. Moreover, women affected by EM showed a higher frequency of rare gene variants in the estrogen pathway genes, potentially affecting MBL plasma levels.

SIGNIFICANCE

A lower functionality of LP in the uterine mucosa may contribute to an unbalanced bacterial environment that could activate endometrial cells. Not only the genotype and the inflammatory condition, but also the estrogen pathway can cause altered MBL levels, thus contributing to changes in the LP functionality.

Gut microbiota in multiple sclerosis and animal models

Multiple sclerosis (MS) is a chronic central nervous system (CNS) neurodegenerative and neuroinflammatory disease marked by a host immune reaction that targets and destroys the neuronal myelin sheath. MS and correlating animal disease models show comorbidities, including intestinal barrier disruption and alterations of the commensal microbiome. It is accepted that diet plays a crucial role in shaping the microbiota composition and overall gastrointestinal (GI) tract health, suggesting an interplay between nutrition and neuroinflammation via the gut-brain axis. Unfortunately, poor host health and diet lead to microbiota modifications that could lead to significant responses in the host, including inflammation and neurobehavioral changes. Beneficial microbial metabolites are essential for host homeostasis and inflammation control. This review will highlight the importance of the gut microbiota in the context of host inflammatory responses in MS and MS animal models. Additionally, microbial community restoration and how it affects MS and GI barrier integrity will be discussed.

Microbiome analysis of serum extracellular vesicles in gestational diabetes patients

AIM

Gestational Diabetes Mellitus (GDM) is among the most common complications during pregnancy, posing serious risks to both the patient's and offspring's health and well-being. Alterations in the maternal microbiome are closely associated with the pathogenesis of GDM, with Extracellular Vesicles (EVs) facilitating communication between microbiota and the host. However, little is known about the relationship between the microbial composition within EVs and the pathogenesis of GDM. Therefore, this study aims to characterize the microbiota within serum EVs of GDM Patients (GDM group) and to identify microbial communities that significantly differ from those in Women With Normal Pregnancies (NonGDM group).

METHODS

Blood samples were collected from both groups of patients, and EVs derived from serum were isolated via centrifugation. Identification and characterization of EVs were performed using transmission electron microscopy and nanoparticle flow cytometry. Microbiome analysis of serum EVs from both groups was conducted using 16S rRNA sequencing.

RESULTS

Results indicated altered diversity in microbial communities within serum EVs of GDM patients. Further analysis at the phylum, family, genus, and species levels revealed that Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were the dominant taxa in the EVs of both the NonGDM and GDM groups. Specifically, Actinobacteria and Firmicutes showed increased relative abundance in GDM group EVs compared to NonGDM, leading to a higher Firmicutes/Bacteroidetes ratio, while Proteobacteria and Bacteroidetes exhibited decreased relative abundance. Tax4Fun analysis revealed enrichment of microbial functions related to amino acid metabolism, carbohydrate metabolism, energy metabolism, and metabolism of cofactors and vitamins in both patient groups.

CONCLUSION

In conclusion, this study reveals a potential correlation between changes in the microbial composition and diversity of serum EVs and the onset and development of GDM. Furthermore, changes in the relative abundance of Actinobacteria, Proteobacteria, Bacteroidetes, and Firmicutes may play an important role in the pathogenesis of GDM.